Method for producing water-absorbent resin powder, and drying device and drying method for particulate hydrous gel

A method for producing water-absorbent resin powder, the method comprising

• a drying step of drying a particulate crosslinked hydrogel polymer obtained by polymerizing a monomer aqueous solution containing a monomer, which is a material of a water-absorbent resin, using a heating device to obtain dried particles, wherein
• the heating device includes:
• a rotary container that contains the particulate crosslinked hydrogel polymer therein and rotates;
• and a plurality of heating tubes that are located within the rotary container, extend in an axial direction of the rotary container, and rotate together with the rotary container, and
• a gel temperature of the particulate crosslinked hydrogel polymer to be subjected to the drying step, the gel temperature being measured by a contact thermometer, is not lower than 50° C.